#include <REGX51.H>

void Delay(unsigned int ms)	;

void main()
{
	unsigned char LEDNum=0;
	P2=~0x01;
	while(1)
	{
		if(P3_1==0)
		{
			Delay(10);
			while(P3_1==0);
			Delay(10);
		
			LEDNum++;
			if(LEDNum>=8)
			{
				LEDNum=0;
			}
			P2=~(0x01<<LEDNum);
		}
		
		if(P3_0==0)
		{
			Delay(10);
			while(P3_0==0);
			Delay(10);
			
			if(LEDNum==0)
			{
				LEDNum=7;
			}else{	
				LEDNum--;
			}
			P2=~(0x01<<LEDNum);
		}
	}
}
void Delay(unsigned int ms)	//@12.000MHz
{
	unsigned char data i, j;
	while(ms--)
	{
		i = 2;
		j = 239;
		do
		{
			while (--j);
		} while (--i);
	}
}
